Caster: Servant of Death
by AbaddontheDevourer
Summary: Harry Potter, Type-Death, slave and master of kings is dragged into the 5th Grail war. Servant Caster is looking for a new life, free of the Gods. Watch as these two unlikely anti-heroes join forces to shake the foundations of Magic
Ok I'll be honest and say I have no idea where this is going. Recently I started to read Fate/Stay Night fanfiction religiously and noticed a severe lack of good fictions involving Caster Medea, the only one I really liked being Path of the King by Neoalfa. The poor woman was pretty much raped and controlled her entire life only to die, be pulled into the Fifth Grail War only to be killed in various gruesome ways. So I decided to write something in which Medea comes out on top. This is a crossover that will focus less on the war and more on the evolving relationship between Harry, Master of Death, and Medea. Yes Harry will be OP as he is the Anthropomorphic Representation of an Aspect of Existence similar to my other story Death in Halkeginia. Suspension of Disbelief is required when reading this, take it as more of a light hearted semi-crackish read unlike my other works which I try to have historical and scientific accuracy. I'm tempted to have this be a mix of Fate and Unlimited Blade Works with a harem for Shirou.

* * *

Harry Potter, holder of too many titles, cursed existence to many in Britain, looked out on the sea of students before him and smiled.

It had been many years since he had killed the Dark Bastard, and for the first time since then he truly felt free. Well as free as you could be when you were on the watch list of every member of the ICW. He had stumbled on that little tidbit while working as an Unspeakable visiting the barracks of the French Aurors. A picture of his head had, to his chagrin, been poorly superimposed on the body of a Nundu with the caption "Warning! Dangerous! Do not approach!" It was at least better than the British one that had the various X ratings of beasts. One of the recruits had deigned to add a XXXXXX level to the chart with his picture next to it. That recruit was now combing the sewers looking for evidence in a 50 year old cold case.

It seems like vaporizing a Dark Lord and all his followers in the middle of a crowded street was a great way to instill fear in the populace. Having killed several wannabe Dark Lords and Ladies since he had killed Voldemort reinforced that fear. At first they had tried to control him, only to find that their spells failed upon touching his skin, potions and poisons no longer worked, and every attempt to bind him failed miserably. It was as if he existed outside of the world, something that had been proven true when he had been visited by two women.

But he digressed and the students were starting to fidget under his stern glower, having never looked away nor blinked in the time it took to recall those thoughts. "For those of you unaware," he drawled in perfect Japanese the look on his face the perfect balance of McGonagall's sternness and Snape's Sneer. "I am Professor Hadrian Potter, and I will be both your Homeroom teacher as well as English teacher during your time here at Homurahara Academy." He swept down the rows, his long coat trailing behind him. Not exactly standard dress but a compulsion or two stopped anyone from reporting him. "I do not expect you to understand the subtle intricacies of my native language. To know the beauty that is Shakespeare, the lessons of Ozymandius or the epic tale of Canterbury." By the time he had said this he was back at the front of the class, his intense glare unnerving even the most stalwart student. "At least…not yet. But make no mistake, by the time you leave my care you will be reciting prose with ease, composing sonnets on whimsy, and be able to discern the true intentions of the writer with but a glance." He slammed his hand against the board, the white screen that covered it rolling upwards to reveal a blackboard full of his elegantly written notes. "For now though, turn to page 5 and be ready to answer my questions."

A few students shivered at the look of glee that he had, but none dared question him as they quickly reviewed Le Morte d'Arthur.

 _A stunning success. If I do say so myself._ Harry thought as he packed away his material for the day. The class had been afraid of him at first, but as it passed they opened up more and more, learning that what he had first shown them was the stick. The carrot had been the epicness of his lesson, and the fact that he whipped out a sword and began to brandish it in a perfect rendition of Mordred slaying Arthur.

As well as no written homework.

Odd how they cheered more for that then when he so valiantly smote Arthur. Anyways once he finished packing up his supplies, he left the school, pausing only to pick up some groceries for dinner. When he got back to his home he was greeted with a flurry of feathers as his faithful companion flew from her perch to his shoulder.

"Hey girl." He greeted, putting down the bags to run a finger down her feathers. "How are you?"

She clicked her beak in annoyance. "I know we haven't been spending that much time together." He apologized. "But I've been busy."

"Bark. Bark bark." Hedwig responded, nipping his finger.

"How about I let you out tonight?" He placated. "The weather is perfect to fly in, and if you get lucky you might find something to eat."

"Bark, bark!"

"Of course. I'll have some bacon ready in the morning." He assured.

"Bark?"

"If that's the kind it takes for you to forgive me." He promised, mentally preparing himself for the long distance travel. He should've known better than to let his companion's supply of iberico bacon dwindle to almost nothing. She could devour almost her own body weight in the salty pork product, and it was only because of her nigh invulnerability that she hadn't died from consumption. Not that he was complaining as the only other companion he had that stuck with him for so long was back in England stirring up trouble. Now that he thought about it her birthday was coming up, and he'd need to get a present. Last time the book on Cthulhu summoning had earned him some points and she gave him a modified 1959 Cadillac Eldorado. He enjoyed driving that around as it had the same enchantments as the infamous Knight Bus in addition to a host of others.

Going over to the window he opened it, allowing his avian friend to fly free. After a quick meal, he headed to the garage and hopped into his car. One of the perks of being who he was, he was able to do magic almost without any repercussions, and in this instance without having to fill out the lengthy paperwork needed to create a portal. The engine roared to life as he slowly pressed down on the pedal, and rather than crashing into the garage door the car began to disappear.

Driving through the portal was an interesting experience and one that he would always remember. There was no long passageway filled with multicolored light or scenes that one would need to question if they had been drugged. It was almost instantaneous, one moment he had been in his garage, the next he was cruising down the A-1, no one any the wiser. Hermione had really outdone herself when she gave him the car, and soon enough he was weaving in and out of traffic, with all the grace of a ballerina. This was good, but at the same time he would've preferred to ride his motorcycle, though it got uncomfortable after riding for a long time.

 _Time to go get Hedwig's bacon._ He thought, gleefully gunning the engine and taking off, his car becoming nothing more than an indiscriminate blur missed in the blink of an eye. _And who knows this might be the start of another epic adventure?_

* * *

She could feel herself dying. The prana that coursed through her, fueling the tenuous hold on this plane of existence, dwindling with every step she took.

Her master, upon learning her true name had all but cut off her supply of prana, keeping her from ever overpowering him. But she was a Caster, the class known for their scheming and strategic planning. Over time she had stored small amounts of prana into various items. She had learned right away that the man she was contracted to was one of the most depraved cowards she ever had the misfortune to meet. The first time she had resisted his orders he had used a command spell to try and ensure her compliance. The foolish man had phrased the command so generically that she was able to resist it, though she did not. It was a trump card for the future, however the punishment for forcing her 'master' to invoke one of the three spells had been…unpleasant.

She had been brutally tortured over the course of a night, the pain excruciating, but she bore it stoically, refusing to so much as whimper. This was her chance at freedom. To live without being the pawn of the Gods, and if she needed to suffer a bit to achieve it then she would take it head on and ask for more.

Afterwards she had forced him to use the second command spell when he tried to force her to assist him in setting up his defenses. She bore the pain he caused, the meager supply of prana he supplied her insufficient to heal the scars he inflicted.

Still though she had succeeded and counted herself lucky that her noble phantasm required so little prana to activate. The amount she had gathered over her imprisonment was barely enough to manifest Rule Breaker for a few minutes, but that was all the time that she needed. Pricking herself with the dagger she managed to sneak up on her former master and bash him over the head with a flower pot, knocking him unconscious. Rather than kill him right away she mustered her remaining energy to create a circle to drain him of every drop of prana, funneling his reserves into herself. It wasn't enough to completely recharge her, not even close, but it would have to do.

She was free.

The thought made her giddy with excitement, even as the crushing realization that it wouldn't last for long threatened to overwhelm her. Struggling she spared as much power as she could to fuel her spell. "Tροψα" A spatial rift opened up, and deposited her close to the sea. From there she dragged her failing body to the edge of a cliff.

"So this is it, huh?" She grimaced, her scars flaring in pain. She looked out on the sea, waiting for the first rays of the rising sun to caress her skin. A part of her wondered if her prana would even last that long. Just as she felt her final reserves slipping away a bird landed on her shoulder, a beautiful snowy owl. "Shoo." She tried to wave the bird off. Owls were a symbol of Athena, one of the Goddesses responsible for forcing her to fall in long with Jason. The fact that it was watching her so closely in her final moments was quite disturbing.

However try as she might the bird refused to leave her alone, and she was forced to stop to conserve the last of her strength. Servants tended to lose most of their memories when they returned to the Throne, but over her long existence and being summoned she managed to remember a few things. "You know, being free is much more painful than I thought it would be." Why was she talking aloud again? It wasn't like the damn bird could answer her; at least she hoped it wouldn't. A bird as beautiful as the one on her shoulder would've been snatched up by Athena in a heartbeat to be used as her divine messenger. While she knew firsthand that owls were quite intelligent, the one that was staring at had an unnatural genius about her that was quite disturbing.

"I'm sure you don't understand me." She spoke. "You're free to fly where ever you want, whenever you want."

"Bark. Bark, bark!" The owl replied, and funnily enough she wasn't sure if she was becoming delusional as she felt herself fading away, or if the bird was that intelligent but at that moment she would've sworn the bird spoke to her in her native Greek, and what a mouth the bird had too. She really hoped that this was actually Athena trapped in the form of a bird, the situation would be quite ironic.

"Don't give me that." Caster said shrugging her shoulder so that the bird fell off. The owl screeched at her before taking to the skies and landing on her head. "Ouch." She yelped feeling the talons dig into her scalp. _Please, someone get rid of this blasted bird._

She was never a religious woman, no matter how much time passed. In fact when the Age of the Gods ended she had done a jig in her little portion of the Throne. Still somethings were surprising enough that she would invoke her tormentor's names, such as this moment. "Di immortals!"

A roaring sound appeared above her, turning she saw a massive white missile hurtling towards her, flames trailing from its rear. A moment later she realized that it wasn't a missile but a car, and that instead of landing into the dirt grill first it leveled itself out. The car hit the ground running, before fishtailing. Her eyes widened, and it would've been comical if she didn't see the massive white backend of the car spinning towards her.

"Σκατά." Was all she could mutter in her native Greek before she was smacked by the bumper and sent flying off the cliff face. _You know this really wasn't how I was expecting to go._ She thought, feeling the rays of the rising sun kiss her skin. A fall like this would've been survivable if she were at full power, but in her current state the end was nigh. She didn't have enough prana in her to cast Tροψα again, so she had little choice but to plummet.

* * *

Harry was not having a good night. First off the place that he normally went to, to get his favorite avian's special treat had run out, so instead he had to drive up north and get one of the pigs to bring back home. Getting to the pig farm had been the easy part, transporting it not so much. Every time he came close to the fence they would run and try to evade him, until finally he had enough and as unsporting as it was hit the entire area with a powerful sleeping charm. From there he levitated a pair of porcines into the back seat and drove off before the sleeping charm wore off, only for his magic use to draw the local Aurors. He had lead them on a merry chase across the majority of Spain several time evading capture by playing chicken with muggle airplanes. He had finally lost them when he entered British airspace. Susan Bones, former member of the DA, his former Second, and current head of the DMLE had not been amused when he pulled the same stunt, eluding capture by flying to France.

His recent obsession with Monty Python took hold and he spent the next 20 minutes taunting the British Aurors with various lines from Quest for the Holy Grail, while driving up and down the border. He'd almost gotten caught by Gabrielle Delacour who had succeeded her father as an Auror Capitaine, driving into a portal to avoid a nasty looking hex she had fired at him. In his haste he hadn't set is home as the destination but rather Hedwig, and he was surprised when he appeared in the skies of Japan. He was even more surprised when the spells on the car began to fail. Nothing Hermione and Luna had ever failed him before, and it took all his quick thinking to remember the necessary spells to slow his momentum. He had gone from an uncontrollable nosedive to a controlled crash as he spun the wheel and the car powerslid towards the cliff.

He hadn't realized he wasn't along until he felt the back end of the car hit something with a solid thunk. Looking out the window his eyes widened to the size of dinner plates as he saw a humanoid figure go flying off the cliff face and towards the waiting water below.

"Shit." He spat, jumping out of the car mid-motion, his right arm glowing with arcane might. He thrust out his hand, fingers spread and curled, and let loose a levitation spell. He used this rather than an _arresto momentum_ as he did not want to slow the person down but rather bring them up to him, not to mention that they were already close to the water and slowing them down would've done nothing but slightly mitigate the impact. He didn't know if there were rocks at the bottom but he wasn't going to risk it. Still the change from rapidly falling to rapidly ascending played havoc on the person's body as he threw his arm back and they soared high into the sky. His left arm shot out, tendrils of magic weaving around them, tightening and slowly bringing them to him. Gently he put the person down on the grass in front of him, Hedwig coming to rest on his car.

The person was wearing a hooded robe of purple and black with gold accenting, over a purple dress and flat black shoes. She wouldn't have looked too out of place in some of the major magic communities, but here in the middle of Fuyuki she'd do nothing but draw stares. Pushing the hood back he couldn't help but take a moment to stare. She was without a doubt one of the most beautiful women he had ever seen, with lavender hair flawless skin and a pixie like face. Her most distinguishing feature though was the knife-like elfin ears that poked out of her hair.

He quickly checked for a pulse only to find none. "Oh shit." He swore before looking to his faithful owl.

"Bark! Bark! Bark!" Hedwig commanded.

He nodded filing that as plan b. "How do you know to dissolve a body again?" The avian familiar turned her head suspiciously refusing to meet his gaze, as he reached into his pocket.

The phone rang a few times before a sleepy female voice answered. "Hello?"

"Hermione!" He called happily. "Thank Merlin you answered me! I've done it again!"

"Harry?" She asked groggily. "It's 3 in the morning here." She yawned, "Whatever you've done I'm sure could wait until morning."

"NO! You don't understand I killed another one." He screamed.

Those were the magic words as Hermione shot up from her bed and began running for her study. She slammed the door shut and activated all the wards on the room preventing anyone from listening in on her before putting the phone back on its cradle and hitting the speakerphone button. "Okay Harry, talk to me, I'm listening."

"I killed another one." He said. "Killed her right as I was finishing up doing the thing I love most in the world."

"A hooker. Alright you killed a hooker. Look I'm sure that she was trying to assassinate you during sex like the past 3. Alright calm down, tell me did she smell like brimstone?"

"No." He said confusedly.

"No? Are you sure, take another whiff. We need to get your story straight, and from where I'm sitting she smells like brimstone. Probably another succubus sent to kill you by one of your many rivals. Though it's possible it was another creature as there are dozens that kill during sex. The important thing is that it was self-defense and that this never hits the light of day." Hermione explained. A steaming cup of coffee appeared on her desk and she drank deeply, the caffeine kick starting her higher motor functions and allowing her to begin to formulate an appropriate defense if Harry were to be taken to court. "Look what you need to do right now is get your hands on some bleach, some hydrogen peroxide, and a boat-load of lye."

"Why don't I just vanish her body?"

"It would leave too much residue that they can use to identify your magic signature." She answered. "You're still in Japan right? Once you finish disposing of the body head west I'll meet you in South Korea at the British Embassy in 15 hours, they don't have an extradition treaty with Japan."

He was about to reply when the corpse at his feet began to cough. "Holy SHIT! The corpse is moving!"

"It must be an inferi!" Hermione screamed into his ear. "Kill it! Kill it with Fire!" Ever since he had taken her to a zombie apocalypse movie her policy when faced with a possible undead was to burn first ask questions never, and let god sort them out.

"δαίμονας πυρκαγιά!" He was about to hurl a bolt of fiendfyre at the corpse when it began to sputter and moan.

"Hermione correct me if I'm wrong but inferi don't make noises right?"

"No they don't why?" His best friend asked.

"Cause the one in front of me is moaning in pain."

"Are you sure that she was dead in the first place?"

"Positive, she didn't have a pulse."

There was a moment of silence, enough to make him feel like he had missed something important and Hermione was about to make him feel stupid for missing it. "Harry. Not everything living has a pulse."

Yup. There it was. "Oh. I forget."

He could hear her sighing on the other end of the line. "Check her with your mage sight."

Sheepishly he activated his other sight, and had to blink to make sure he was seeing what he was seeing. "Hermione, normal witches and magi don't bleed magic right."

"No they don't." She answered. "If the magic is bleeding from them then that means she's got a core rupture." There was shuffling followed by a dull thud as a heavy tome slammed onto her desk. "Listen to me very carefully Harry. If the woman's core completely empties she'll die."

"Is there any way to heal her?" He placed a hand on the woman's forehead trying to find out what happened.

Hermione was quiet for a few minutes, before saying in a small voice. "Harry, do you have IT with you?"

He didn't need to ask what she meant, as there was only one thing that they both referred to as IT. "I do." He answered. "But you told me not to use it on anyone."

"She doesn't need a full dose. A few milliliters will suffice to repair the damage."

"I'm going to need something more than that to give her an exact dosage." He replied conjuring a goblet and filling it with water. From around his neck he withdrew a blood red stone and submerged it into the water. "She's about 163cm and no more than 51 kg."

"Hold on." Hermione said, he heard a pen scribbling on paper as she worked out the calculations. Meanwhile the water was beginning to turn the same color as the stone. "Okay, 50ml should be enough to heal her."

"50ml, got it." He responded, rummaging around in his pocket for something to measure. Finally he withdrew an empty sample bottle of vodka that was 50ml in size. Carefully he filled it before sitting the woman up and gently prying her mouth open. "Shhh." He whispered as caringly as he could. "This should help you."

She was too weak to do anything but nod, as he tipped the vodka bottle into her mouth. He didn't pour it all in one go, allowing her to sip it, so that she wouldn't choke.

The effects were almost instantaneous, as she let loose a banshee like scream. In his mage vison he could see the concentrated power of the elixir flowing through her, supercharging her every cell with raw magic. She shot up, their foreheads smacking together with a meaty thunk.

"Damn!" "Σκατά!" They both swore. Harry clutched his forehead in pain, unceremoniously letting the woman go, allowing her to fall back against the hard dirt.

"Harry! Can you hear me?!" Hermione screamed from over the phone. "Were you wrong? Is she a zombie? Did she bite you?"

Blindly groping for the phone, he felt the cold plastic, and brought it up to his ear. "Hermione I'm here. It worked."

"That's good." His best friend answered. "Do you need me to go there?"

Shaking the stars out of his eyes he took a look at the woman before him. While she was much stronger than she was before she was still leaking a small amount of magic. "No I think I'm fine for now. Thanks though, and I'll call you if I need anything else."

"Okay." She said disappointingly. "But you don't need to call me just when something goes wrong. I don't talk to you enough anymore."

"I'll talk to you again this weekend." He promised before hanging up. Gathering the woman in his arms he carried her over to his car, and deposited her in the back seat before driving off towards his home. If it were anyone else he'd drop them off at the nearest hospital but, since the woman was obviously a magic user of some sort he felt that she might need continued treatments, especially for her condition.

* * *

Virtual cookies to anyone that can spot the various movie references in this chapter.


End file.
